Kiwi scientists make atomic 'breakthrough'

University of Otago scientists have made a "major physics breakthrough" with the development of a technique to consistently isolate and capture a fast-moving single atom.

A team of four researchers from the university's physics department are believed to be the first to isolate and photograph the Rubidium 85 atom.

The three-year project used laser cooling technology to slow a group of atoms, before a laser beam, or "optical tweezers", isolated and held one atom.

Lead researcher Mikkel Andersen said individual atoms were consistently isolated, which meant "a major step" toward using the atoms to build ultra-fast quantum-logic computers capable of performing complex information-processing tasks.

"Our method provides a way to deliver those atoms needed to build this type of computer, and it is now possible to get a set of ten atoms held or trapped at the one time," Dr Andersen said.

"You need a set of 30 atoms if you want to build a quantum computer that is capable of performing certain tasks better than existing computers, so this is a big step towards successfully doing that.

"What we have done moves the frontier of what scientists can do and gives us deterministic control of the smallest building blocks in our world."

Dr Andersen said within three weeks of first trapping the atom, new experiments previously not thought possible were under way.

The next step was to try and generate a "kind of atomic romance" between the atoms, he said.

"We need to generate communication between the atoms where they can feel each other, so when they are apart they stay entangled and don't forget each other even from a distance. This is the property that a quantum computer uses to do tasks simultaneously."

Dr Andersen said neutral atoms such as the Rubidium 85 were notoriously difficult to pin down because they could not be held by electrical fields.

"I learnt at elementary school that it is impossible to see a single atom through a microscope. Well, my elementary school teacher was wrong."